Note: Descriptions are shown in the official language in which they were submitted.
CA 022044~6 1997-0~-0~
CONNECTOR DEVICE WITH GV~KVOLTAGE PROTECTION
RA~ROUND OF THE lNV~. llON
Field of the Invention
The present invention relates to a connector device for
connecting a data processing device or communication equipment
to a communication line and, more particularly, to a connector
plug having an overvoltage protection function and adapted to
be inserted into a connector socket, and to an adapter having
an overvoltage protection function and used to connect a
connector plug with a connector socket.
Related Arts
In recent years, information co~llnication technologies
using communication lines such as public telephone lines have
been developed. This development permits easy access to a
large-scale database throughcommunication lines frompersonal
computers equipped in offices and homes, and permits network
services to exchange information between personal computers
through telephone lines, for instance.
Thecommunicationlinesofthistypeextendineverysphere
of an urban area and also extend between city areas. An
individual communication line is led into an office or home and
is connected through interior wiring with a data processing
device, including a computer, or communication equipment
including a telephone set, facsimile, modem. Hereinafter, the
data processing device, communication equipment, etc. are
collectively referred to as electronic devices or electronic
equipment. Recently, connectors of a modular type (modular
plug and modular jack) have been used widely. By inserting a
modular plug, connected with a signal-transmission cable
extending from electronic equipment, into a modular jack
connected with the interior wiring, the electronic equipment
can be connected easily to the communication line.
CA 022044~6 1997-0~-0~
If an excessive voltage caused by inductive lightning is
applied to communication lines extending in an area where
lightning occurs, a surge voltage is applied to electronic
devices connected with these communication lines. This
sometimes leadsto damagetoelectronic devices anddestruction
of data.
Conventionally, to protect an electronic device from a
surge voltage, an overvoltage protection circuit which absorbs
the surge voltage is incorporated into a protector which is
provided in a lead-in port for the communication line in an
office or home, to thereby prevent the application of the surge
voltage to an electronic device. The overvoltage protection
circuit, which is usually comprised of a surge protection
element such as an arrester, including a gas-tube arrester, or
a zinc oxide varistor, is connected between a pair of signal
lines of the communication line. Sometimes, multi-stage
protection is afforded by a protection circuit provided with
agas-tube arrester andazinc oxidevaristorwhich arearranged
in two stages, or by further inserting a diode bridge circuit
at the later stage of the protection circuit.
However, these surge protection elements for the
overvoltage protection circuit have their characteristics
which change with time bythe repetitive application of impulse
current thereto. In addition, it is generally difficult to see
to what degree the surge protection device has deteriorated in
its characteristics. For this reason, the electronic device
cannot be sufficiently protected from overvoltage by the
protectorprovidedwithsuchanovervoltageprotectioncircuit.
Moreover, the protector equipped with the overvoltage
protection circuit of this type must be maintained by a
qualified electric worker, so that the maintenance and
modification oftheprotectorcannotbe carriedoutbytheuser.
Therefore, the user cannot take any measures although knowing
that the surge voltage caused by inductive lightning may
CA 022044~6 1997-0~-0
adversely affect electronic equipment.
SU~MARY OF THE lNVL.. llON
Anobjectofthepresentinventionistoprovideaconnector
device with overvoltage protection, which can easily and
effectively protect electronic equipment, including
communication equipment and a data processing device, from an
overvoltage caused by inductive lightning etc. and applied via
a communication line.
Another object of the present invention is to provide a
connector device with overvoltage protection, which is easy in
assembly, excellent in mass productivity, and therefore less
costly to manufacture.
Stillanotherobjectofthepresentinventionistoprovide
a connector device with overvoltage protection, which is
suitable for use as an adapter used to connect a plug with a
socket, especially, as a modular adapter for establishing
connection between a modular plug and a modular jack.
The connector device with overvoltage protection
according to the present invention comprises a main body having
a plug section adapted to be detachably inserted into an
external connector socket which has two socket contacts
electrically connected individually to two conductor wires of
a first signal-transmission cable; two first contact members
disposed in the plug section, these two first contact members
being electrically connected individually to the two socket
contacts when the plug section is inserted into the external
connector socket; and an overvoltage absorption solid-state
device disposed in the main body and having two terminals which
are electrically connected individually to the two first
contact members. The two first contact members are connected
or adapted to be connected respectively to two conductor wires
of a second signal-transmission cable which is connected or
adapted to be connected with external electronic equipment.
CA 022044~6 1997-0~-0~
According to the connector device, having the overvoltage
absorption solid-state device, of this invention, external
electronic equipment including a data processing device,
communicationequipment,etc.canbeeffectivelyprotectedfrom
overvoltage by connecting the electronic equipment to a
communication line via the connector device. Moreover, by
using the connector device in place of an existing connector
device, the protection against overvoltage applied from the
outside can be achieved by the user, without the need of
modifying electrical equipment and its component parts such as
a protector whose maintenance, check, etc. should be made by
a qualified electric worker. As a result, the electronic
equipment can be protected effectively from a surge voltage
causedby inductive lightningor the like. Since a solid-state
deviceisusedforovervoltage absorption,the connector device
can be made compact in size, so that it is suitable for use as
a modular plug or a modular adapter.
Preferably,theovervoltageabsorptionsolid-statedevice
is comprised of a silicon bidirectional diode-thyristor. With
this arrangement, the overvoltage absorption solid-state
device can be made compact, and the protection against
overvoltage can be provided with high reliability.
This connector device can be embodied as a connector plug
(more specifically, a connector plug with or without a second
signal-tr~nqm-~sion cable). In this case, preferably, the
main body is formed with a cable accommodation space for
accommodating therein one end portion of the second signal-
tr~n~m~sion cable.
Each of the two conductor wires of the second signal-
tr~ns~-~sion cable is formed by a sheathed conductor wire
consisting of a conductor and an insulator which covers the
conductor or formed by a bare conductor wire consisting of a
conductor.
Inthecaseoftheconnectordeviceofatypehavingasecond
CA 022044~6 1997-0~-0~
signal-transmission cable, that is, a second signal-
transmission cable is included in the connector device as a
device component, the plug section of the main body of the
connector device is adapted to be detachably inserted into a
modular jack which serves as an external connector socket, and
amodularcableisusedasthesecondsignal-transmissioncable,
whereby the connector device suitable for use as a modular plug
can be provided.
Preferably, each of the first contact members is disposed
in contact with an associated one conductor of the conductor
wires of the second signal-tr~n~ sion cable. More
preferably, each of the first contact members has a contact pin
which is disposed in contact with the conductor. In case that
the second signal-transmission cable has sheathed conductor
wires, the contactpinbreaksthe insulator andcomes incontact
with the conductor. With this arrangement, the electrical
connection between the first contact members and the second
signal-tr~nsm;ssion cable can be made surely.
Thesecondsignal-transmission cable mayhave asheathfor
sheathing the two conductor wires. In this case, preferably,
the cable accommodation space has a first space section which
is open to that end face of the main body which is disposed on
a side remote from the plug section and accommodates therein
the second signal-transmission cable with the sheath and a
second space section which communicates with the first space
section and accommodates therein the second signal-
transmission cable with the sheath stripped. This preferred
embodiment enables the main body of the connector device to
surely hold the second signal-transmission cable, and is
convenient for establishing the electrical connection between
the second signal-transmission cable and the first contact
members.
Preferably, the plug section of the main body is formed
with two grooves. Each of these grooves accommodates therein
CA 022044~6 1997-0~-0~
an associated one of the two first contact members. With this
arrangement, the first contact members can be positioned in
their places in the main body. More preferably, the two first
contact members are arranged adjacently to the overvoltage
absorption solid-state device. Each of the first contact
members has a portion thereof disposed in contact with a
corresponding one of the two terminals of the overvoltage
absorptionsolid-statedeviceattheoutsideofthetwogrooves.
With this arrangement, the electrical connection between
component parts of the connector device and the assembly of the
connector device are made easy.
Preferably, the main body is formed with a recess
accommodating therein the overvoltage absorption solid-state
device. The two terminals of the overvoltage absorption
solid-state device are exposed from an outer face of the
solid-state device. The connector device further includes a
pair of wiring members. At least part of each of the wiring
members is disposed in the recess of the main body. Each of
the wiring members has a first end thereof electrically
connected with an associated one of the two conductor wires of
the second signal-transmission cable, a second end thereof
disposed in contact with an associated one of the two first
contact members, and an intermediate portion thereof disposed
in contact with an associated one of the two terminals of the
overvoltage absorption solid-state device. With this
arrangement, the connection between the first contact members
of the connector device and the second signal-trAnsmission
cable and the connection between the first contact members and
the overvoltage absorption device can be made easily with the
aidofthewiringmembers,wherebytheassemblyoftheconnector
device is made easy.
The two conductor wires of the second signal-trAn~m;ssion
cable may be comprised of bare conductor wires. In this case,
preferably,thecableaccommodationspacecommunicateswiththe
CA 022044~6 1997-0~-0~
recess. The two bare conductor wires of the second signal-
transmission cable protrude from the cable accommodation space
intotherecess. Thefirstendofeachwiringmemberisdisposed
in contact with an associated one of those two bare conductor
wires of the second signal-transmission cable which protrude
into the recess. According to this preferred embodiment, the
electrical connection between the wiring members and the first
contact members can be established easily, and the assembly of
the connector device can be carried out more easily.
Preferably, the recess has an opening which opens to one
of those external surfaces of the main body which extend in a
longitudinal direction of the main body. The wiring members
are disposed in the recess on a side remote from the opening
of the recess, as viewed in a height direction of the main body.
The overvoltage absorption solid-state device is disposed
adjacently to the wiring members in the recess, as viewed in
the height direction of the main body. The connector device
further includes a lid member which closes at least part of the
opening of the recess. The lid member cooperates with the main
body to hold the wiring members, the overvoltage absorption
solid-state device, and the two first contact members.
According to this preferred embodiment, the assembly of the
connector device and the electrical connection between device
component parts are made more easy.
Morepreferably,theplugsectionofthemainbodyisformed
with two grooves. The recess is adjacent to the plug section
in the longitudinal direction of the main body and communicates
with the two grooves of the plug section. Each of the grooves
accommodates therein an associatedone of the two first contact
members and part of an associated one of the wiring members.
The lidmember has a longitudinal lidsection thereof extending
in thelongitudinal directionofthemainbody alongtheopening
of the recess, and a vertical lid section thereof extending in
the height direction of the main body between the overvoltage
CA 022044~6 1997-0~-0~
absorptionsolid-statedeviceandthetwofirstcontactmembers.
The main body has a wall thereof disposed on the side remote
from the opening of the recess, as viewed in the longitudinal
direction of the main body. The wall cooperates with the plug
section to define the recess, and cooperates with the
longitudinal lid section of the lid member to hold the wiring
members and the overvoltage absorption solid-state device.
The plug section cooperates with the vertical lid section of
the lid member to hold the two first contact members.
Preferably, each of the first contact members is formed at its
opposite edges with one or more engagement projections or
engagement recesses. Each of said plug section and said
vertical lid section is formed with one or more engagement
recesses or engagement projections with which said associated
one or more engagement projections or engagement recesses
engage.
According to these preferred embodiments, the electrical
connection between device component parts is made reliable by
the mechanical contact/engagement structure of the connector
device without the need of processing such as soldering, and
the connector device can be made very strong in structure.
The present invention can be applied to a connector device
connectedwithanexternalsignal-tr~n~ sioncable. Thatis,
according to another embodiment of the present invention
different from the embodiments having the main body formed with
the cable accommodation space, the main body is formed with a
socket section which is adapted to detachably receive an
external connectorplug,theexternal connectorplughavingtwo
plug contacts electrically connected individually to the two
conductor wires of the second signal-transmission cable. The
connector device further includes two second contact members
disposed in the socket section. These two second contact
members are electrically connected with the two first contact
members, respectively. The two second contact members are
CA 022044~6 1997-0~-0~
electricallyconnectedwiththetwoplugcontacts,respectively,
when the external connector plug is inserted into the socket
section. With this arrangement, the connector device is
provided which is suitable for use as an adapter interposed
between the connector plug and the connector socket for
establishing connection therebetween. By interposing this
adapter between the existing connector plug and the existing
connector socket, overvoltage protection can be achieved.
In the case of the adapter which is interposed between a
modular plug and a modular jack, the external connector socket
is the modular jack, and the external connector plug is the
modular plug, and the socket section is adapted to detachably
receive the modular plug.
Like the preferred embodiments suitable for use as a
connector plug, in the preferred embodiment suitable for use
as an adapter, a pair of wiring members may be arranged in the
recess of the main body of the connector device, whereby the
assembly of the connector device is made easy.
Preferably, the recess communicates with the socket
section. Each of the second contact members is formed
integrally with an associated one of the wiring members. With
this arrangement, the assembly of the connector device is made
more easy.
Like the preferred embodiments suitable for use as a
connector plug, in the preferred embodiment which includes the
wiring members formed integrally with the second contact
members, a lid member for holding the wiring members,
overvoltage absorption solid-state device, and first contact
members may be provided, so as to permit more easy assembly of
the connector device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional view showing a modular
CA 022044~6 1997-0~-0
plug with overvoltage protection according to a first
embodiment of the present invention;
FIG. 2 is a sectional view showing an assembly process for
the modular plug shown in FIG. l;
FIG. 3 is a perspective view showing a silicon
bidirectional diode-thyristor incorporatedinthe modularplug
shown in FIG. l;
FIG. 4 is a perspective view showing a modification of the
bidirectional diode-thyristor;
FIG. 5 is a view showing a device construction of the
bidirectional diode-thyristor shown in FIG. 1;
FIG.6isaviewshowinganelectricallyequivalentcircuit
of the thyristor shown in FIG. 5;
FIG. 7 is a graph showing the voltage V - current I
characteristics of the bidirectional diode-thyristor;
FIG. 8 is a view showing, by way of example, an overvoltage
protection circuit using the bidirectional diode-thyristor;
FIG. 9 is an operation characteristic diagram showing the
overvoltage protection function of the bidirectional diode-
thyristor in the circuit shown in FIG. 8;
FIG. 10 is a view showing an example of basic application
of the bidirectional diode-thyristor;
FIG. 11 is a view showing another example of application
of the thyristor;
FIG. 12 is a longitudinal sectional view showing a modular
plug with overvoltage protection according to a second
embodiment of the present invention;
FIG. 13 is an explodedperspectiveviewof the modular plug
shown in FIG. 12;
FIG. 14 is a longitudinalsectionalview of an adapterwith
overvoltage protection according to a third embodiment of the
present invention,togetherwith anexternalmodularsocket and
an external modular plug;
FIG. 15 is a longitudinal sectional view of an adapter
CA 022044~6 1997-0~-0~
according to a fourth embodiment of the present invention: and
FIG. 16 is a sectional view showing a modification of the
adapter shown in FIG. 15.
DETAILED DESCRIPTION OF ~K~KK~ EMBODIMENTS
With reference to the drawings, connector devices with
overvoltage protection according to several preferred
embodiments of the present invention will be described.
First, a connector device according to a first embodiment
of the present invention will be described, which device is
suitable for use as a modular plug with overvoltage protection
(hereinafter referred to as plug). Referring to FIG. 1, the
plug 1 has a plug body 10 made of a material consisting mainly
of polycarbonate, for instance.
The plug body 10 has dimensions and shape conforming to
the FCC (Federal Communications Comm) standard, and is
detachably plugged in an external modular socket (hereinafter
referred to as socket) which is disposed on, e.g., the wall
surface of a house and paired with the plug. The socket is
configured in the same way as a modular socket (modular jack)
shown by reference numeral 40 in FIG. 14. The socket 40 has,
e.g., two socket contacts 41, electrically connected
individually to, e.g., two conductor wires 71 of a first
signal-transmission cable led in an indoor space, such as for
example a public telephone line 70.
As shown in FIG. 1, the plug body 10 is formed, as a whole,
into a rectangular parallelepiped shape, is provided at its
front side with a plug section 10a adapted to be detachably
inserted into the socket 40, and is provided at its rear side
with a cable accommodation space 12, 13 which is adapted to
receive one end portion of a second signal-transmission cable
30. The second signal-tr~n~m-~sion cable 30 has, e.g., two
conductor wires 33 each consisting of a conductor wire 33 and
CA 022044~6 1997-0~-0~
an inner sheath 32 which covers the wire 33. The two sheathed
conductor wires 32, 33 are covered with an outer sheath 31. The
second signal-transmission cable 30 is preferably comprised of
a modular cable, and has another end thereof connected with,
e.g., a conventionally known modular plug. The plug is inserted
into a modular jack provided on external electronic equipment
such as a data processing device or communication equipment,
not shown.
The cable accommodation space consists of a first space
10 section 12 for accommodating therein the second signal-
transmission cable 30 with the outer sheath and an insertion
hole 13 (a second space section) for accommodating therein the
second signal-transmission cable 30 with the outer sheath
stripped (i.e., sheathed conductor wire 32, 33). These two
15 space sections 12 and 13 communicate to each other, and extend
in the longitudinal direction of the plug body 10. The first
space section 12 is open to the rear end face of the plug body
10. Reference numeral 12a denotes the opening of the first
space section 12.
At the front end of the plug body 10, a lever 17 is provided
integrally with the upper wall of the plug body. Specifically,
the lever 17 is hinge-connected with the plug body 10, and is
adapted to be pivoted around the hinge-connected portion in the
directions toward and away from the plug body 10. At opposite
25 edges of a longitudinal intermediate portion of the lever 17,
shoulders (not shown) are provided which protrude outward in
the width direction of the lever 17.
The plug body 10 accommodates therein a silicon
bidirectional diode-thyristor (more generally, an overvoltage
30 absorption solid-state device), which is a principal element
of the modular plug 1. Two terminals 21 of the thyristor 20
are exposed on the bottom surface of the thyristor 20. The
thyristor 20 can be configured by a current type silicon
surge-protective device (CSSPD), which is available from, for
CA 022044~6 l997-0~-0
13
example, Shindengen Kogyo in Japan.
In order to arrange the thyristor 20 in the plug body 10
as illustrated, an upper half of the plug body 10 and a lower
half thereof formed with a thyristor accommodation recess are
molded separately, and these halves are joined to each other
after the thyristor 20 is put into the recess of the lower half
of the plug body, for instance. Alternatively, so-called
insertmoldingmaybeperformedinwhichtheplugbodyismolded,
with the thyristor 20 disposed in a mold for plug body molding.
The plug section lOa is provided with two or more contact
grooves 14. L-shaped connection contact plates (first contact
members) 15arepressedinto, e.g., twoofthese contact grooves
14, respectively, as shown in FIG. 2. Each contact plate 15
has a horizontal portion thereof extending in the longitudinal
direction of the plug body 10 and a vertical portion thereof
extending in the height direction of the plug body 10. Two
needle-shaped contact pins 16 are formed at the upper end of
the vertical portion. Each contact plate 15 is in contact at
its contact pins 16 with the associated conductor wire 33 of
thesecondsignal-transmissioncable30soastobeelectrically
connected therewith, and is in contact at the upper surface of
the horizontal portion with the corresponding exposed terminal
21 of the thyristor 20 to establish electrical connection
therewith. At least part of the outer surface of the front and
lower edges of the contact plate 15 is exposed to the outside
of the contact groove14. When the plugsection lOais inserted
into the socket 40, the exposed outer surface of the contact
plate 15 is brought into contact with the socket contact 41 at
the outside of the contact groove 14, so that electrical
connection therebetween is established.
In assembling the modular plug 1 configured as described
above, a predetermined length, which is substantially equal to
the length of the insertion hole 13, of the outer insulator 31
of the second signal-transmission cable 30 is removed. Then,
CA 022044~6 1997-0~-0
14
the two sheathed signal lines 32, 33 are inserted into the
insertion hole 13 (second space section) from the first space
section 12 of the cable accommodation space, as shown in FIG.
1. As a result, the sheathed conductor wires 32, 33 at the
distal end portion of the second signal-transmission cable 30
are arranged in the second space section 13, and those portions
31, 32, and 33 which are covered by the outer insulator at the
distal end portion of the cable are arranged in the first space
section 12.
Next,thetwocontactplates15arepressedintothecontact
grooves.14 towardthe insertion hole 13 by using an FCC standard
handtool(notshown). Thecontactpinsl6Ofeachcontactplate
15 break the inner insulator 32 of the associated second
signal-transmission cable and come in contact with the
associatedsignalline33. Atthistime,thehorizontalportion
of each contact plate 15 comes in contact with the associated
tqr~;n~l 21 of the thyristor 20 incorporated in the plug body
10. Thus, electrical connection is established between the
contact plate 15 and the signal line 33 and between the contact
plate 15 and the thyristor terminal 21. As a result, the
thyristor 20 is interposed between two contact plates 15 and,
in turn, between two signal lines 33.
In the meantime, it is not essential to make the
press-fitting of the connection contact plate 15 in order to
establish the connection between the contact plate 15 and the
thyristorterminal21. Alternatively,thecontactplate15and
the thyristor terminal 21 may be connected in advance by means
of a lead wire, bonding wire, etc.
Next, the bottom wall 11 of the plug body 10 is deformed
by heating from the state shown in FIG. 2 to the state shown
in FIG. 1, so that the distal end portion of the signal-
transmission cable 30 covered with the sheath 31 is pressed on
the inner surface of upper wall of the plug body 10 whereby the
distal end portion of the signal-transmission cable 30 is held
CA 022044~6 1997-0~-0
in the plug body 10.
By connecting the thus assembled modular plug 1 with the
modular socket 40, electronic equipment such as a data
processing device can be connected with the telephone line. On
5 thisoccasion,whentheplugsectionl0aofthepluglisinserted
into the socket 40, the shoulders of the lever 17 are pressed
down toward the plug body 10 by protrusions (denoted by
reference numeral 40a in FIG. 14) formed on the inner surface
of the upper wall of the socket. When the plug section 10a is
further pushed into the socket 40 so that the shoulders of the
lever 17 pass the protrusions 40a, the lever 17 is restored by
its own elasticity in the direction away from the plug body 10.
The rear end faces of the shoulders of the lever 17 engage with
the end face of the protrusions 40a, so that the plug 1 is
connected with the socket 40 so as not to be removed therefrom.
When the plug 1 is to be removed from the socket 40, the plug
is pulledout ofthesocketwith the lever17beingpresseddown.
The following is a description of the silicon
bidirectional diode-thyristor 20 incorporated, as an
overvoltage absorption solid-state device, in the modular plug
body 10 .
In this embodiment, asurface-mount-packagedthyristor20
is used, which is shown by way of example in FIG. 3. This
thyristor 20 has, for example, a length L of 7.6 mm, a width
W of 4 mm, and a height H of 2.8 mm. In place of this, a
button-packaged thyristor 20' may be used. This thyristor 20'
has, for example, a diameter D of 4.15 mm and a height H of 1.7
mm.
The overvoltage absorption solid-state device of this
embodiment is a bidirectional thyristor having a planar type
5-layer construction shown in FIG. 5 without a gate electrode,
and is manufactured by using a silicon base material. This
silicon bidirectional diode-thyristor 20 is equivalent to two
thyristors connected in inverse parallel with each other, as
CA 022044~6 l997-0~-0
16
shown in FIG. 6. In other words, in place of the bidirectional
diode-thyristor 20, an overvoltage absorption solid-state
device consisting of two thyristors etc. can be used.
In FIGS. 5 and 6, symbols P1, N2, P3, N4 and P5 indicate
five layers of the thyristor 20, and symbols J1, J2, J3 and J4
indicate four junctions of the thyristor 20. Symbols i1 and
i2 each indicatecurrent flow andR1, R2,R3andR4each indicate
resistance. Symbols (+) and (-) indicate the anode and cathode
electrodes of the thyristor 20, respectively. The thyristor
is brought in a conduction state when an overvoltage is applied
between the electrodes of the thyristor.
The bidirectional diode-thyristor 20 has voltage V-
current I characteristics as shown in FIG. 7. Specifically,
when the applied voltage V to the thyristor 20 is low, the
junctionJ2iskeptinareversebiasstate,sothatthethyristor
20is keptinanoffstate(region AinFIG.7). Whentheapplied
voltage V approaches the breakdown voltage of junction J2,
avalanchebreakdownoccursatthejunctionJ2. Whentheapplied
voltage exceeds the breakover voltage Vgo (suffixes "1" and"2"
attachedtothesymbolinFIG. 7 indicatepositive andnegative,
respectively), current i2 flows just under the P1 layer (region
B), and a voltage drop (i2 X R2) caused by the current i2 is
applied to the junction J2. When the voltage drop reaches the
diffusion potential of junction J2, the injection of carrier
from the P1 layer to the N2 layer starts, so that the flow of
current i1 takes place (region C). As a result, the sum of the
current amplification factor of a transistor consisting of
N2-P3-N4 layers having current dependency and the current
amplification factor of a transistor consisting of P1-N2-P3
layers becomes ~1", so that the thyristor 20 becomes in an on
state. After the thyristor 20 becomes conductive, the on
voltageVTappearswhichvariesaccordingtotheforwardvoltage
CA 022044~6 1997-0~-0
drop of PN junction diode (region D).
Theabovefunctionofthethyristor20occursinaccordance
with the polarity of voltage applied to the thyristor 20, and
therefore the thyristor 20 shows the V-I characteristics of
bipolar symmetry shown in FIG. 7.
As shown by way of example in FIG. 8, the bidirectional
diode-thyristor 20 having the above-mentioned V-I
characteristics is mounted at the stage preceding a protected
circuit (data processing device) which is connected with a line
81 having a predetermined load RL As is apparent from the
operating characteristic of the thyristor 20 shown in FIG. 9,
during the normal operation in which a voltage VB lower than
the breakover voltage Vgo is applied to the line 81, the
thyristor 20 is not conductive, and hence line current iL is
supplied to the protected circuit 90 as it is.
In the case where an excessive surge voltage Vsurge caused
by inductive lightning etc. is applied to the line 81, when the
applied voltage V to the thyristor 20 exceeds the breakover
voltage Vgo, the thyristor 20 conducts momentarily, so that the
surgecurrentIsurgeflowsintothethyristor20. At thistime,
the on voltage VT appears across the thyristor 20. Therefore,
an excessive surge voltage Vsurge is not applied to the
protected circuit 90. The surge current Isurge decreases
gradually, and when it reduces to the holding current IH (FIGS.
7 and 9) of the thyristor 20 or less, the thyristor is turned
off, so that the aforementioned normal operation mode is
restored.
Therefore,inthecasewherethesignal-transmissioncable
30 is connected with the modular socket 40 through the modular
plug 1 provided with the thyristor 20 which has the
aforementioned operating characteristic and which is
interposed between the signal lines 33 of the signal-
CA 022044~6 l997-0~-0
18
transmission cable 30 (line 81) extending from the data
processing device 90, the thyristor 20 connected between the
contact plates 15 is renderedconductive when the surge voltage
Vsurge from the communication line 70 (FIG. 14) caused by
inductive lightning etc. is applied between the contact plates
15 each of which is interposed between the socket contact 41
and the signal line 33 of the signal-transmission cable 30.
Upon conduction of the thyristor 20, the surge current Isurge
which varies in dependence on the surge voltage Vsurge is
bypassed to the thyristor 20. The voltage applied between the
signal lines 33 of the signal-transmission cable 30 is kept at
the voltage across the thyristor 20 (on voltage VT).
Specifically, the surge voltage Vsurge applied between the
contact plates 15 of the modular plug 1 from the communication
line via the protector, interior wiring, and socket 40 is
absorbed by the conduction of the thyristor 20. As a result,
the surge voltage Vsurge is prevented from being applied to the
data processing device via the signal-transmission cable 30,
so that the data processing device can be protected effectively
from the surge voltage Vsurge-
The above-described modular plug 1 is convenient in that
it can be used freely by the user. By using the plug 1, it is
possible to prevent the surge voltage Vsurge applied via the
communication line 70 from being propagated to the data
processing device. Therefore, even if an overvoltage
protection circuit consisting of a gas-tube arrester, zinc
oxide varistor, etc. is not incorporated in the protector, the
user can take protective measures against surge voltage easily
and effectively. Specifically, even the ordinary user
unqualified as electricworkercan effectivelyprotectthe data
processing device from a surge voltage caused by inductive
lightning etc.
In the above embodiment, the connector device using the
CA 022044~6 1997-0~-0
19
first signal-transmission cable and the second signal-
transmission cable each consisting of two signal lines has been
described. However, this invention is not limited thereto.
For example, in the case of using the signal-transmission cable
5 having many signal lines, in order to protect the protected
device 90 from the surge voltage applied between a particular
pair of signal lines among these signal lines, a thyristor 20
may be interposed between the particular paired signal lines
82, as shown in FIG. 10. To protect the protected device 90
10 from the surge voltage applied between each of signal lines and
the ground line, two silicon bidirectional diode-thyristors 20
may be interposed in cascade between the paired lines 83, with
the connection point of these thyristors 20 grounded, as shown
in FIG. 11.
Next, a modular plug with overvoltage protection according
to a second embodiment of the present invention will be
described with reference to FIGS. 12 and 13.
The plug of this embodiment is characterized in that it
can be assembled more easily. This plug has the same basic
20 configuration as that of the first embodiment. In this regard,
those elements which are the same as or similar to corresponding
elements of the first embodiment will be described briefly and
each of which is denoted by reference numeral equal to the sum
of the reference numeral of a corresponding element of the first
25 embodiment and ~100~.
A plug 101 includes a plug body 110, two first contact
members 115, and a silicon bidirectional diode-thyristor 120.
The plug body 110 has a plug section llOa adapted to be inserted
into a modular jack corresponding to the element 40 shown in
30 FIG. 14 (hereinafter referred simply to as a modular jack 40).
A lever 117 is integrally formed on the upper wall llOe of the
plug body 110.
The plug body 110 is formed with insertion holes 112 and
113 into which the distal end portion of a second signal-
CA 022044~6 1997-0~-0
transmission cable 130 is inserted. The large-diameter
insertion hole 112 is open to the rear end face of the plug body
110, and accommodates therein the distal end portion, covered
with a sheath 131, of the signal-transmission cable 130. The
two small-diameter insertion holes 113 communicate with the
large-diameterinsertionhole,andaccommodatethereintwobare
conductor wires 133 at the distal end portion of the
signal-transmission cable, respectively. In place of the two
insertion holes 113, one insertion hole which collectively
accommodates two conductor wires 133 may be provided. In a
state where the signal-transmission cable 130 is inserted into
the insertion holes 112 and 113, a part 111 of bottom wall of
the plug body 110 is deformed by heating toward the cable 130
whereby the cable 130 is undetachably held in the insertion
1~ holes 112 and 113.
The plug body 110 is formed at its intermediate portion
with a recess llOb whose lower face is open. The recess llOb
is definedbythe upper wall llOe, thefront wall (plugsection)
llOa, and a partition wall llOf of the plug body 110. The
partition wall llOf is formed with the insertion hole 113. The
recess llOb communicates with the insertion hole 113. The plug
section llOa is formed with two or more contact grooves llOd
communicating with the recess llOb. Each contact groove llOd
is open to the front and bottom faces of the plug section llOa.
2~ The recess llOb accommodates therein respective rear end
portions 116a and intermediate portions 116c of wiring members
116 and the whole of the thyristor 120. Each of particular two
contact grooves llOd receives therein anassociatedonecontact
member 115 and mainly a front end portion 116b of an associated
one wiring member 116. The width of the contact groove llOd
andthethicknessofthecontactmember115andthewiringmember
116, which are received in the contact groove, are slightly
greater than the thickness of the socket contact 41 (FIG. 14).
When the plug 101 is inserted into the socket 40, the contact
CA 022044~6 1997-0~-0~
member 115 comes in contact at its arcuate corner 115d with the
socket contact 41, so that it is electrically connected with
the conductor wire 71 of the signal-transmission cable
(telephone line) via the socket contact 41.
5Reference numeral 118 in FIGS. 12 and 13 denotes a lid
member fitted to the recess llOb. The wiring body 116 and the
thyristor 120 are held in the recess llOb by the lid member 118.
Specifically, each wiring member 116 which is made of a
conductive metal plate is formed into an inverse U shape as a
whole, as viewed in the longitudinal cross section of the plug,
and extends along the front endface of the partition wall llOf,
the inner surface of the upper wall llOe and the rear end face
of the front wall llOa of the plug body 110. The wiring member
116 has a U-shaped rear end portion 116a with spring property.
The U-shaped rear end portion 116a consists of a first vertical
section extending downward vertically from the intermediate
portion 116c, a bent section, and a second vertical section
extendingupwardverticallyinparallel with thefirst vertical
section. A tip end (first end) 116d of the second vertical
section is formed into a Y shape, so that an associated one bare
conductor wire 133, protruding from the insertion hole 113, of
the signal-transmission cable 130 is held in the Y-shaped tip
end 116d. The distal end portion of the conductor wire 133 has
its outer peripheral surface disposed in contact with the
Y-shaped tip end 116d of the wiring member 116. Preferably,
the tip end face of the conductor wire 133 abuts on the rear
face of the first vertical section of the U-shaped rear end
portion 116a (FIG. 12). Thus, each conductor wire 133 and the
associated wiring member 116 are electrically connected
reliably to each other.
Each wiring member 116 has a U-shaped front end portion
116b, similar to the U-shaped rear end portion 116a, and the
intermediate portion 116c. A vertical section of the U-shaped
front end 116b has a length which is shorter than that of the
CA 022044~6 1997-0~-0~
rear end portion 116a. The tip end of the front end portion
116b is not formed into a Y shape.
The lid member 118 has a first horizontal section 118a
extendinghorizontallyalongtheopeningllOcoftherecessllOb
just under the U-shaped rear end portion 116a of the wiring
member 116, a first vertical section 118b extending vertically
from the first horizontal section 118a to the thyristor 120
along the U-shaped rear end portion 116a, a second horizontal
section 118c extending horizontally from the first vertical
section 118b to the contact member 115 along the bottom surface
of the thyristor 120, and a second vertical section 118d
extending vertically from the second horizontal section 118c
to the upper wall of the plug body 110 between the thyristor
120 and the contact member 115. That is, as viewed in the
longitudinal cross section of the plug, the lid member 118 is
formed into a staircase shape. The lid member 118 holds the
wiring member 116 and the thyristor 120 in their places in the
recess llOb, while it cooperates with the partition wall and
the upper wall of the plug 110 to establish stable contact
between thethyristorterminal 121 andawideportion116ewhich
extends outward in the plug width direction from the
intermediate portion 116c of the wiring member.
In FIG. 12, reference numeral 122 denotes a spacer which
is disposed arbitrarily between the lid member 118 and the
thyristor 120.
Each contact member 115 is provided at its center with a
notch 115a whose upper end is open, and is formed into a U shape
as a whole. The contact member is formed with engagement
projections 115b and 115c at the rear edge thereof, and
engagement projections 115e and 115f at the front edge thereof.
The central notch 115a of the contact members 115 receives
a U-shaped front end portion of the associated wiring member
116. The engagement projections 115b and 115c of the contact
member 115 engage with engagement recesses 118e and 118f formed
CA 022044~6 1997-0~-0
23
on the front end face of the second vertical section 118d of
the lid member 118, respectively. The engagement projection
115eofthecontactmember115 engageswith an engagement recess
llOg formed on the inner face of the contact-groove-formed-
portion of the plug section 110. Further, the engagementprojection 115f engages with the bottom face llOh of the
contact-groove-formed-portion of the plug section 110. With
this arrangement, the wiring member 116 and the contact member
115 are connected with each other mechanically and
electrically.
The wide portion 116c of each wiring member 116 comes in
contact with an associated one exposed terminal 121 of the
thyristor 120, so that the wiring member 116 is electrically
connected with the thyristor terminal 121.
In assembling the plug 101 configured as described above,
the distal end portion of the signal-transmission cable 130
whose outer sheath 131 of a predetermined length has been
stripped is inserted into the insertion holes 112 and 113. The
sheath-removed distal end portion of the cable is accommodated
20 in the insertion hole 113, and the sheathed distal end portion
of the cable is accommodated in the insertion hole 112. In this
state, each wiring member 116 is inserted into the recess llOb
of the plug body 110 through the recess opening llOc. At this
time, the U-shaped front end portion 116b of the wiring member
116isinsertedintoanassociatedoneparticularcontactgroove
llOd. By arrangingpart of the wiringmember 116 in the contact
groove llOd, the wiring member 116 is disposed in the recess
llOb of the plug body while it is positioned in place in the
width direction of the plug.
Next, the thyristor 120 is mounted on the upper surface
of the second horizontal section of the lid member 118 via the
spacer 122, and the lid member 118 is fitted into the recess
llOb of the plug body through the opening llOc and is fixed to
the plug body 110. As a result, a pair of wiring members 116
CA 022044~6 1997-0~-0
24
are pressed against the inner surface of the upper wall llOe
of the plug body 110 by the lid member 118 via the spacer 122
and the thyristor 120. Therefore, the U-shaped rear end
portions 116a of the wiring members 116 are brought in contact
with the two bare conductor wires 133, respectively, so that
electrical connection between the wiring members 116 and the
bare conductor wires 133 is established. Also, the two
thyristor terminals 121 come in contact with the wide portions
116eofthewiringmembers116,respectively,sothatelectrical
connection between the thyristor terminals 121 and the wiring
members 116 is established.
Next, the two contact members 115 are inserted into the
particular two contact grooves llOd. As a result, the U-shaped
front end portion 116b of each wiring member 116 fits in the
central notch 115a of the corresponding contact member 115, and
the engagement projections 115b, 115c, 115e and 115f of the
contact member 115 engage with the engagement recesses llOe,
llOf and llOg of the lid member 118 and the plug section 110
and the bottom face llOh of the plug section, respectively. As
a result, the contact members 115 are held undetachably in the
contact grooves llOd, and electrical connection between the
contact members 115 and the wiring members 116 is established.
According to the plug 101 configured as described above,
the assemblyandelectricalconnection canbe completedeasily.
That is, the electrical connection between the lead wire 130
and the contact members 115 and between the lead wire 130 and
the thyristor 120 can be established surely by the mechanical
contact/engagement provided between the aforementioned
components of the plug 101, without the need of processing such
assoldering. Moreover,partofeachwiringmember116andeach
contact member 115 are disposed in the corresponding contact
groove llOd, and the contact members 115, the wiring members
116, and the thyristor 120 are held by the lid member 118 and
the plug body 110. Further, the lead wire 130 is positioned
CA 022044~6 1997-0~-0~
and held stably in the insertion holes 112 and 113. With this
arrangement, the elements 115, 116 and 120 can be positioned
stably in the plug body 110, electrical connection between the
elements 115, 116, 120 and 130 can be established stably, and
very strong construction can be provided.
Next, a connector device according to a third embodiment
of the present invention will be described with reference to
FIG. 14.
The connector device of this embodiment is characterized
in that it is suitable for use as an adapter which is interposed
between a modular plug and a modular socket for establishing
interconnection therebetween.
In FIG. 14, reference numeral 40 denotes a conventionally
known modular socket (external connector socket). This socket
40 has socket contacts 41 electrically connected individually
to, e.g., two signal lines 71 of the telephone line (first
signal-tr~nsm;~sion cable) 70 which is lead in the interior of
a house. Reference numeral 50 denotes a conventionally known
modular plug (external connector plug) attached to the distal
end portion of a signal-transmission cable (second signal-
tr~n~m;ssion cable) 30 which extends from external electronic
equipment such as a data processing device. This plug 50 has
two plugcontacts 51electrically connectedindividually totwo
conductor wires of the signal-tr~n~m;ssion cable 30.
Reference numeral 60 denotes an adapter having an overvoltage
protection function according to this embodiment.
The adapter 60 includes an adapter body 61. The adapter
body 61 is provided at its front portion with a plug section
61a corresponding to the element lOa shown in FIG. 1, and is
provided at its rearportion with a socket section 62 into which
the modular plug 50 is detachably inserted. Specifically, at
the rear side of the adapterbody 61, aplug accommodation space
(socket section 62) for accommodating therein the plug 50 is
defined by an upper wall 61b, an L-shaped lower wall 61c, and
CA 022044~6 1997-0~-0
26
opposite side walls (not shown) of the adapter body 61.
The adapter body 61 holds two first contact members 63,
two second contact members 64, and a silicon bidirectional
diode-thyristor 20. Each second contact member 64 is formed
integrally with an associated one first contact member 63. To
accommodate the elements 20, 63 and 64 in the adapter body 61,
an upper half and a lower half of the adapter body 61 are
fabricated separately, for instance. In this case, the upper
and lower halves are joined to each other, with the thyristor
20 received in a thyristor accommodation recess formed in the
upperhalfandthecontactmembers63and64receivedinacontact
member accommodation recess formed in the lower half.
The first contact members 63 each have a vertical section
thereof extending downward along the front end face of the
adapter body 61, and a horizontal section thereof extending
rearwardfromtheverticalsection. Thehorizontalsectionhas
its upperfacewhichis disposedin contactwith acorresponding
one thyristor terminal 21 exposed to the outside of the
thyristor 20. The front portion of theL-shaped contact member
63 is disposedwithin an associatedoneofcontact grooves which
are formed in the plug section 61a. The second contact members
64eachhaveaverticalsectionthereofextendingdownwardalong
the inner face of the vertical section of the L-shaped lower
wall 61c of the adapter body 61 from the rear end of the
horizontal section of the associated first contact member 63,
ahorizontalsection thereof extendingrearwardalongthe inner
face of the horizontal section of the L-shaped lower wall 61c
from the vertical section, and a contact section thereof
extending upward obliquely from the horizontal section toward
the front portion of the adapter body. The contact section has
a spring property.
When the plug section 61a of the adapter 60 is inserted
into the external socket 40, the two first contact members 63
of the adapter 60areelectrically connectedwith thetwo socket
CA 022044~6 1997-0~-0~
contacts 41 of the socket 40. When the external plug 50 is
inserted into the socket section 62 of the adapter 60, the two
plug contacts 51 of the plug 50 are electrically connected with
the two second contact members 64 of the adapter 60. Thus, the
two conductor wires 33 of the signal-tr~ns~;.ssion cable 30
extending from a data processing device etc. are electrically
connected with the two conductor wires 71 of the telephone line
70 via the plug 50, the adapter 60, and the socket 40. That
is, the adapter 60 has a function of electrically
interconnecting the socket contact 41 and the plug contact 51.
In FIG. 14, reference numeral 61 denotes an engagement
projection which is provided at the upper edge of opening on
the rear end face of the adapter body 61. This engagement
projection 61d engages with a shoulder of a lever 50a of the
plug50when the plugis insertedintothe adapter60, tothereby
detachably hold the plug 50 in the socket section 62.
If an overvoltage is applied between a pair of contact
members 63 of the adapter 60 via the telephone line 70, the
silicon bidirectional diode-thyristor 20 interposed between
the contact members 63 is rendered conductive to absorb the
overvoltage.
According to the adapter 60 configured as describe above,
the existing modular plug 50, attached to the distal end of the
signal-tr~ns~;ssion cable 30 extending from a data processing
device, is connected through the adapter 60 with the existing
modular socket 40 that is originally devised for exclusive use
with the plug 50. Simply by doing this, if a surge voltage
(corresponding to Vsurge in FIG. 9) caused by inductive
lightning is applied to the socket 40 through the communication
line 70, the surge voltage is absorbed by the thyristor 20 of
the adapter 60. As a result, the surge voltage is prevented
from being propagated to the plug 50, and in turn, to the data
processing device via the signal-transmission cable 30.
CA 022044~6 1997-0~-0
28
Therefore, the data processing device can be protectedfrom the
surge voltage effectively. Moreover, the adapter 60 can be
interposed easilyby the user between the socket 40 andthe plug
50, so that preventive measures against surge voltage can be
taken.
Next, a connector device with overvoltage protection
according to a fourth embodiment of the present invention will
be described with reference to FIG. 15.
The connector device of this embodiment is common to that
of the third embodiment in that it is configured in the form
of modularadapterhavingafunctionof overvoltageprotection,
and common to that of the second embodiment in that wiring
members are employed for easy assembly of the connector device.
Therefore, those elements which are the same as or s, mi 1 ~r
to the elements shown in FIGS. 12, 13 and 14 relating to the
second and third embodiments are denoted by like numerals in
FIG. 15. The following is a brief description of an adapter
of this embodiment.
Referring to FIG. 15, an adapter body 261 of an adapter
260 includes a plug section 210a thereof adapted to be inserted
into an external modular socket (corresponding to the socket
40 in FIG. 14) and a modular socket section 262 thereof adapted
to receive an external modular plug (corresponding to the plug
50 in FIG. 14).
25 - The adapter body 261 cooperates with a lid member 218 to
hold therein a silicon bidirectional diode-thyristor 220, two
first contact members 215, and two wiring members 216. The lid
member 218 has a horizontal section thereof extending in the
longitudinal direction of the adapter along an opening of a
recess 210b of the adapter body 261 and a vertical section
thereof extendingintheheightdirectionoftheadapterbetween
the thyristor 220 and the first contact member 215. The
horizontal section of the lid member 218 supports a spacer 222,
thethyristor220, andthewiringmember 216 incooperationwith
CA 022044~6 l997-0~-0
29
the adapter body 261, while the vertical section of the lid
member 218 supports the first contact member 215 and the wiring
member 216 in cooperation with the adapter body 261.
The wiring members 216 each have a rear end portion 216a
thereof extending horizontally in the longitudinal direction
of the adapter, aU-shapedfront endportion216b thereof fitted
in a central notch 215a formed in a corresponding one first
contact member 215, and an intermediate portion 216c thereof
disposed in contact with an associated one terminal of the
thyristor 220. Each second contact member 264 is formed
integrally with an associated one wiring member 216. The
connectingportionbetweenthewiringmember216andthecontact
member 264 extends from the recess 210b of the adapter 260 into
the socket section 262 via an opening formed at the upper half
15 portionofapartitionwall261c'(correspondingtothevertical
section of the lower wall 61c of the adapter body shown in FIG.
14) of the adapter body 261. The second contact members 261c
each have a vertical section thereof extending along the
partition wall 261c', a horizontal section thereof extending
20 along the inner surface of the lower wall 261c of the adapter
body, and a contact section thereof extending upward obliquely
from the horizontal section toward the front portion of the
adapter body. The horizontal section has a sp~ing property.
Inordertoassemblethewiringmembers216intotheadapter
25 body 261, the wiring members 216 are inserted in the
longitudinal directionofthe adaptertowardthe socketsection
262 and the recess 210b of the adapter body through the rear
end opening of the adapter body. After the wiring members 216
are inserted into the adapter body, the thyristor 220 and the
spacer 222 are disposed within the recess 210b, and the lid
member 218 is fitted in the opening 210c of the recess 210b to
thereby retain these elements 220 and 222. Then, the contact
members 215 are mountedbetween the lid member 218 andthe front
wall of the adapter body 261, thereby completing the assembly
CA 022044~6 1997-0~-0
of the adapter 260.
Other configuration and effects of the adapter 260 are the
same as those of the devices of the second and third embodiments,
so that the explanation is omitted.
According to the adapter 260 configured as described above,
by merely mounting the adapter 260 between the existing modular
plug and the existing modular socket, a surge voltage caused
by inductive lightning and applied from a communication line
can be absorbed effectively by the thyristor 220 incorporated
10 in the adapter 260. That is, by merely mounting the adapter
260 on the communication signal line for a data processing
device, especially at the connecting portion between the
modular socket and the modular plug, the data processing device
can be protected from the surge voltage easily and effectively.
Moreover, since the wiring members 216 and the contact
members 264 are integral with each other in this adapter 260,
the entire construction of the adapter can be simplified, and
the number of its component parts can be reduced.
FIG. 16 shows a modification of the adapter 260 shown in
FIG. 15.
An adapter 360 shown in FIG. 16 differs from the adapter
260 shown in FIG. 15 in that the external modular plug is disposed
in an inverted position when inserted into the socket section
of the adapter. Regarding this difference, each second contact
member 364 consists of a horizontal section thereof extending
rearward in the longitudinal direction of the adapter from the
rear end of a corresponding one wiring member 316 along the upper
wall inner surface of an adapter body 361, and a contact section
thereof extending downward obliquely from the horizontal
section toward the front portion of the adapter.
Other configuration and effects of the adapter 360 are the
same as those of the adapter 260 shown in FIG. 15, so that the
explanation is omitted.
The present invention is not limited to the first to fourth
CA 022044~6 l997-0~-0
31
embodiments and the aforementioned modification.
For example, in each of the first to fourth embodiments,
the modular plug 1 or 101 or the adapter 60 or 260 with
overvoltage protection is adapted to be inserted into the
modular socket 40 provided on the wall surface of house.
However, the plug 1 or 101 or the adapter 60 may be adapted to
beinsertedintoasocketprovidedonthedataprocessingdevice.
In this case as well, overvoltage is absorbed by the silicon
bidirectional diode-thyristor 20 incorporated in the plug or
adapter, thereby preventing the propagation of surge voltage
to the data processing device via the socket of the device.
Intheaboveembodiments,theexamplesinwhichthepresent
invention is applied to a modular type connector have been
described. However, the present invention is also applicable
tootherconnectorconstructionsin asimilarmanner. Further,
the number of connection termin~ls in the connector is not
especially limited. When the connector has three or more
connection terminAls (signal lines), a bidirectional diode-
thyristorshouldbeinterposedbetweentheconnectionter~in~ls
to which a surge voltage is likely applied. In this case, for
those wiring members which need not be connected with the
thyristor 20, no wide intermediate portions are formed, to
thereby prevent the wiring members from contacting with the
terminal 21 of the thyristor 20.
The adapter of the present invention may have shape,
dimensions, etc. thereof determined so as to conform to the FCC
standard.
The constructional features of the first to fourth
embodimentscanbecombinedvariously. Forexample,thedevice
30 showninFIG.l,whichusesthesecondsignal-tr~ns~issioncable
comprised of sheathed conductor wires, may be modified so that
the cable comprised of bare conductor wires as shown in FIG.
13 can be used. Inversely, the devices shown in FIGS. 12 and
13 may be modified so that the cable comprised of sheathed
CA 022044~6 1997-0~-0
conductor wires can be used.
The present invention can be modified variously without
departing from the spirit and scope thereof.
